How?

DTI Global Watch Missions enable small groups of UK experts to visit leading overseas technology organisations to learn lessons about innovation and its implementation, to benefit industries and organisations. Sweden, Denmark and Germany were visited by the Mission to fact-find about their successful operating experience with housing with very low space heating demand.

When?

It was first published in 2007. This is a report of a DTI Global Watch Mission, organised by CIRIA with the support of DTI in November-December 2006.

Why?

It is intended to help industry reduce the carbon in housing, by learning from existing examples.

Who should read this?

Anyone who is involved in housebuilding, or planning, that is interested in reducing energy use and greenhouse gas emissions in new and existing housing.

Background

Changes to building regulations have radically improved standards of thermal efficiency in new housing over the past three decades, however yet higher levels of efficiency will be required if the UK is to meet long-term emission targets. A seminar titled Towards zero carbon housing – lessons from Northern Europe, chaired by CIRIA's Chief Executive Bill Healy, took place on 16 March 2007, Church House Conference Centre, Westminster.

The seminar presented the Mission findings from a study of best practice approaches to the reduction of fossil fuel energy use and associated emissions in Denmark, Sweden and Germany, with a view to informing and influencing future housing design and energy systems in the UK.

Content

This 68-page book gives those findings:

Experience in Sweden, Denmark and Germany shows that there are no technical barriers to the construction of low-rise housing of conventional appearance but with very low energy demand for space heating. With correct design and operation, fully acceptable comfort conditions can be provided in both winter and summer. Investigation of the application of the same design principles in medium- and high-rise housing is required

Successful application of low energy design principles depends on attention to detail in design and construction, which has implications for education and training courses, and then on ensuring that occupants understand how to operate the energy systems in the dwellings

Achieving the lowest levels of energy consumption may not be cost-effective, but very substantial improvements can be made without increasing overall costs if the value of future energy savings can be capitalised. In UK social housing this may require a change in funding arrangements

Refurbishment to similar levels of energy performance, without great impact on appearance or internal space, is technically possible but again may not be cost- effective at present energy costs

The design principles for low energy housing promoted by the PHI have been proven in practice. The standards are prescriptive but capable of modification (as in some developments visited) to reflect local conditions. They require evaluation for UK climate conditions

Air-tightness will be a key determinant of energy consumption in future housing. Mechanical ventilation with heat recovery will become a normal feature in new-build properties. Systems suitable for small dwellings are now being marketed in the UK and there is much relevant experience in Sweden and Denmark

Sweden has extensive experience in heat pumps, and again there are no technical barriers to application, but the market for ground-source systems still requires government support. These systems have superior performance but air-to-air heat pumps, which are less expensive, offer perhaps the optimum long-term route for supplying top-up heat and hot water in low energy housing

Germany has a high level of interest in micro-CHP, and expects to have commercial fuel cell systems on the market in three years. The direction of development is, however, orientated towards larger systems suitable for apartment blocks. Technical collaboration should be encouraged

Novel insulation and heat storage materials are available on the German market and their effectiveness in the UK should be investigated

Financial incentives, in the form of grants, interest subsidies and preferential rates for the purchase of renewable energy, have significantly stimulated the market for new energy systems in the countries visited and continue to support those markets. This is likely to be the case in the UK also.